From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2C838EC1103 for ; Mon, 23 Feb 2026 16:18:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7768B6B0095; Mon, 23 Feb 2026 11:18:41 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 725866B0096; Mon, 23 Feb 2026 11:18:41 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5DBC66B0098; Mon, 23 Feb 2026 11:18:41 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 4B7346B0095 for ; Mon, 23 Feb 2026 11:18:41 -0500 (EST) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 167E81A022F for ; Mon, 23 Feb 2026 16:18:41 +0000 (UTC) X-FDA: 84476229642.20.2EFB48B Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf03.hostedemail.com (Postfix) with ESMTP id 3AA0D20003 for ; Mon, 23 Feb 2026 16:18:39 +0000 (UTC) Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="YEnC/BJ7"; spf=pass (imf03.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1771863519; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=UWTCm6YVB1RWkZzGvZBcjmH6CX1vnsWpzDMoxYrQQUc=; b=hm1qhGvTc5goHH5IDnmfTV0ftCHMrtXVuM5kpyFRtEbA+yYJdj7lAXi+qUNIfHCAgg4lOa tan8rFNzBWdQG+vqPrctr1oBFbIF4IMzGq83xiZkAAulyPHLwL8NXZszAvlZFDlp9OKU6p StqEfDIeFbLv4o3RA6QCM1eX6Xijdro= ARC-Authentication-Results: i=1; imf03.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="YEnC/BJ7"; spf=pass (imf03.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1771863519; a=rsa-sha256; cv=none; b=vNuxaADrq7LKINU3Lq9V6vvGM4eb0n6oRfyVSyYB44gtTN2J1YwfEr+Tp98rs+VTQbBZMx G/y6LEHo5t+GW7cwaXK8mJ+z1ldk2NER+7vVRzLqRqNzx3Dzyslv0e0EGfI2EYPxsiS+tN qAVWgot5GxsGWKxrrtgpMQ0W0ouW2PQ= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 751A660137; Mon, 23 Feb 2026 16:18:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 217A4C116C6; Mon, 23 Feb 2026 16:18:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771863518; bh=ENSbuCfjK9K9qz+F1QE9v10noBk4EeAtynmQ7eTgJA4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=YEnC/BJ7YyhFoowsZI0FWuJYftp2IbxDrX+JOlaVZIHCtTRK5H9iLszRJLsbUYdWy lwnLrg/i2lYRCQUZXxXOfkqACPnRrHK04HIY78DlzO55W80Ad5w7OrCsTc9ZD6YVVA CmqcCx111G1GJBl5B5fHXG+JLWAawS3moQ4hJaMzSXr+wlqgwZyy2TLDr6pplVvi+f PIRQMwh1ICqFnlhi6xEgSOf6uQu+A9gGbvdqi2qzB6lpzlA1YqgtgdKtu/4bh4tl3V AA4v53sz8w4BAOuORtdceaoP/FiSfypya0e3/QxPQWcqKNMQ4w5Tb7f8UhrX3TaP13 161hEcU36My6g== Message-ID: Date: Mon, 23 Feb 2026 17:18:24 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 3/4] arch, mm: consolidate empty_zero_page To: Mike Rapoport , Andrew Morton Cc: Andreas Larsson , Borislav Petkov , Brian Cain , Catalin Marinas , "Christophe Leroy (CS GROUP)" , "David S. Miller" , Dave Hansen , Dinh Nguyen , Geert Uytterhoeven , Guo Ren , Helge Deller , Huacai Chen , Ingo Molnar , Johannes Berg , John Paul Adrian Glaubitz , "Liam R. Howlett" , Lorenzo Stoakes , Madhavan Srinivasan , Magnus Lindholm , Matt Turner , Max Filippov , Michael Ellerman , Michal Hocko , Michal Simek , Palmer Dabbelt , Richard Weinberger , Russell King , Stafford Horne , Suren Baghdasaryan , Thomas Gleixner , Vineet Gupta , Vlastimil Babka , Will Deacon , linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, loongarch@lists.linux.dev, linux-m68k@lists.linux-m68k.org, linux-openrisc@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-mm@kvack.org, x86@kernel.org References: <20260209144058.2092871-1-rppt@kernel.org> <20260209144058.2092871-4-rppt@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <20260209144058.2092871-4-rppt@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 3AA0D20003 X-Stat-Signature: tcfdqdqr5zkaiw478hmkwpw1amqatyo1 X-Rspam-User: X-HE-Tag: 1771863519-153195 X-HE-Meta: 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 m/UkxCj6 J3AjgyQGlKxvsXMC/FFPzS9cmXcSItR9sO9mepvyIgr/l8CA8YpfPindea94b5ZgdVJhAjX+1pbfslXV3QwEcCTghrUwsGcv79t7EcX2S+IaiYzaAzPXjiBj27InDKywg36LnZRvBMXpbZ83xjGplDWZ3Hlz652N/Ii52J0KbrszLrnbAGo1e4eqAju9NsKdaVOvY6gS0acadXlGO1mGyOBNqniCLN4tsUg+5R0fMhYCdqC30674rLAqn8Pi09IyV3ca1k5nFM3QnnhgI3Yrf2Vgw0sroh7WTmLkSYa0w8d71RvNTZFEZ+k1o6Ty7jk3h/RYzQlyHsmuIVXbDJeTzjdCblLlY+ZhnyOjxvRQMYC4DtCU= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2/9/26 15:40, Mike Rapoport wrote: > From: "Mike Rapoport (Microsoft)" > > Reduce 22 declarations of empty_zero_page to 3 and 23 declarations of > ZERO_PAGE() to 4. > > Every architecture defines empty_zero_page that way or another, but for the > most of them it is always a page aligned page in BSS and most definitions > of ZERO_PAGE do virt_to_page(empty_zero_page). > > Move Linus vetted x86 definition of empty_zero_page and ZERO_PAGE() to the > core MM and drop these definitions in architectures that do not implement > colored zero page (MIPS and s390). > > ZERO_PAGE() remains a macro because turning it to a wrapper for a static > inline causes severe pain in header dependencies. > > For the most part the change is mechanical, with these being noteworthy: > > * alpha: aliased empty_zero_page with ZERO_PGE that was also used for boot > parameters. Switching to a generic empty_zero_page removes the aliasing > and keeps ZERO_PGE for boot parameters only > * arm64: uses __pa_symbol() in ZERO_PAGE() so that definition of > ZERO_PAGE() is kept intact. > * m68k/parisc/um: allocated empty_zero_page from memblock, > although they do not support zero page coloring and having it in BSS > will work fine. > * sparc64 can have empty_zero_page in BSS rather allocate it, but it > can't use virt_to_page() for BSS. Keep it's definition of ZERO_PAGE() > but instead of allocating it, make mem_map_zero point to > empty_zero_page. > * sh: used empty_zero_page for boot parameters at the very early boot. > Rename the parameters page to boot_params_page and let sh use the generic > empty_zero_page. > * hexagon: had an amusing comment about empty_zero_page > > /* A handy thing to have if one has the RAM. Declared in head.S */ > > that unfortunately had to go :) > > Acked-by: Helge Deller # parisc > Tested-by: Helge Deller # parisc > Reviewed-by: Christophe Leroy (CS GROUP) > Signed-off-by: Mike Rapoport (Microsoft) > --- Acked-by: David Hildenbrand (Arm) -- Cheers, David